Loss of fibronectin in human breast cancer.

The distribution of fibronectin was studied in normal human breast tissue and in breast tumors. In normal tissues and in benign tumors, fibronectin was present in basal laminae and on the cellular surfaces of myoepithelial and secretory cells. A partial loss of (pericellular) fibronectin was seen in atypical dystrophies, and a complete disappearance of pericellular and basement membrane-bound fibronectin was observed in invasive adenocarcinoma.